Releasably interlocked grinding mechanism



May 8, 1945. N ,OBEDIN 2,3 75,680

RELEASABLY INTERLOCKED GRINDING MECHANISM Filed Oct. 30, 1944 NATHAN OBEDIN INVENTOR ATTORNEY a UNITED, ESTATE shaped motor driven rotary cutter.

responding parts Patented May 8, 1945 S1 PAT Eur omca 1 RELEASABLY QINTERLOCKEDGRINDING MECHANISM e Nathanjobedin, Brooklyn, N. Y. I Application. OctoberfSO, 1944, Serial No. 561,108

' 2 claims. (01.519-348) This invention relates to improvements in portable cloth cutting machines of the kindthat are adapted to be moved about byhand on aclothcutting table, the cutting machine having a disk- An object of this invention is to provide an improved grinding device which is pivotally mounted on the motor and having two rotatably supported grinding wheels straddling the cutter and adaptedto be jointly swung into contact with the cutter for. grinding and sharpening during its rotation by the motor. a

Another object of this invention is toprovide cup-shaped retainers .for rotatably supporting the grinding wheelsbyinterlocking engagement.

and without cementing the grinding wheelsin the retainers. i 3 i a Another object of this invention is. toprovide means for .detachably. securing each of the grinding wheels for rotation on an axle, the said means mounted on an axle, theretainer having apertures positioned on diametrically opposite sides .1 and to provide keyways in the. grinding wheel,} and a clamping disk having a central aperture l the cutter 3 and pins on diametricallyopposite sides of the .1

aperture, the pins passing through the keyways and through the apertures in the retainer and a serving to transmit torque to the retainer.

on the grinding wheel Another object of this invention is to provide d an annular leaf spring having corrugations therein and adapted to be secured intermediatea clamping disk and a grinding wheel in a retainer to absorb shock imparted to the grinding wheel. Withthe above and other-objects inview, the invention will be hereinafter more particularly described, and the combination and arrangement of parts will be shown in the accompanying drawing and pointed out in the claims which form part of this specification.

Reference will now be had to the drawing,

wherein like numerals of reference designate corthroughout the several views,

in which:

Figure 1 is a perspective view of a cloth-cutting machine having a .diSk-shaped motor driven rotary cutter and provided with an improved duplex 1 grinding mechanism embodying the invention.

Figure 2 is a central cross-sectional view of the duplex grinding mechanism, showing releasably mounted grinding wheels.

Figure 3 is a plan View of a grinding wheel 1,

retainer.

2'0 comprisingv a cup-shaped retainer rotatablyj Figure 4 is'a plan view of a releasable grinding wheel. i r

Figure 51s a plan viewof a pin-carrying disk for a grinding wheel. a Figure 6 is a plan view of i an having corrugations therein.

; Figure '7 is a central cross-sectional .view of a modified grinding wheel mounting, showing'the annular spring inserted between the grinding mechanical interlock for the grinding wheelwith the wheel retainer. The mechanical interlock ing of the grinding wheel with thewheel retainer 1 does away with the heating operation and the.

resultant obnoxious smell created thereby.

In theiillustrated embodiment 'of the invention,

thenumeral ll] indicates a portable clothcutting machinehaving a disk-shaped cutter H driven by an;;electric motorilz and. movable on cutting tableszon a base 13 integral with the motor, as is wellknown in the art;

For the purpose of grinding and sharpening the disk-shaped cutter H during its rotation,

there is provided a grinding attachment l5, comprising a housing l6 having a pivotpin I! passing. therethrough. The pm I! is received in an arm l8 fixed to the motor housing.

The grinding attachment I5 has two grinding wheels l9, which are spaced apart from each other. The wheels 19 are housed in cup-shaped wheel retainers 2|]. Each retainer has an inte-j gral spindle 2| designed for rotation in a bearing member 22. The attachment I5 is thus pivotally mounted and may be swung down to bring the grinding wheels I9 into grinding engagement with the cutter H.

The bearing members 22 have threads 23 on their outer surfaces whichengage threads in arms 24 integral with the housing l6. Screws .25 threadedin thespindles 2| hold the retainers 20 in rotatable relation in the bearing members 22. The bearing members 22 may be adjustably rotated to bring the grinding wheels l9 to or away i from the cutter I l. a e The mechanism disclosed herewith for release 3 annular spring ably securing each grinding wheel I9 to a wheel retainer 20 consists in part in forming keyways 28 extending through the flange 2'! of the grinding wheel [9. I employ a centrally apertured disk 28 having a plurality of pins 29 integral with the disk and positioned diametrically thereof. A central aperture 30 in the disk 28 is preferably countersunk to receive the head of a flat head screw 3 I. V

I also provide apertures 32 positioned diametrically of the wheel retainer 20. The apertures 32 are in alinement with the keyways 26 in the grinding wheel I9 and with the pins 29 in the disk 28. In practice, the spindle 2| has-an enlarged head 33 by means of which the spindle-is suitably fixed to the Wheel retainer 20.

In operation, a grinding wheel I9 is placed in a wheel retainer 20 with the keyways :25 and the apertures 32 in alinement. The disk 28 is then mounted inside a hollow portion 34 of the grinding wheel .19, with :the :pins 29 passing through the keyways 26 and through the apertures 32.

' The screw. 31 is then threaded into atapped hole in the head 33 and tightened to bring the grinding wheel 13 into engagement with the inner surface of the wheel retainer 20..

Grin-ding mechanism of the character here .described is subject to shocks and .a degree of vibration. To readily cushion and absorb these shocks and vibrations I provide an annular resilient spring 36 having a corrugated or undulated surface. The spring 356 is placed between the cupshaped. retaining member 20 and the grinding wheel r9. I

. Thespring 36 serves to press the grinding whee-1 19 into frictional engagement with grinding wheel 13 firmly, thus avoiding unneces- .sary "strain. The resilient spring .35 distributes the :pressure evenly when the disk 23 is tightened against the grinding wheel and the wheel is in pressure contact with the cup-shapedwheel re.- tainer .20. The :pins 12.9 transmit the ..load and there is no necessity for relying .uponexcessive frictional pressure for driving power.

In accordance with, the patent statutes I have described and illustrated the preferred embodiment of my invention, but it will be understood that various changes and modifications can be made therein without departing from the spirit of the invention as defined by the appended claims.

Iclaim:

1. In a grinding mechanism having grinding wheels, releasable mounting. meansior said grinding wheels, said mounting'comprising a rotatably supported cup-shaped wheel retainer, a grinding wheel having an outside diameter adapted to enter said re'tainen said grinding wheel having a hollow portion at the face opposite said retainer,

said grinding wheel having keyways extending 'therethrough and being positioned diametrically thereof, said cup-shaped retainer having apertures in alinement with said keyways, a disk having a central aperture and pins integral therewith and positioned diametrically thereof, said pins being in alinement with said keywa/ys and with saidapertures' in said retainer, and releasable means threaded intolsaid retainer and pass? ing through said central aperture in :said disk for releasably securing said grinding Wheel to said wheel-retainer.

2. In a grinding mechanism having rinding wheels, releasable .mountingimeans for said grind- :ing wheels, .said mounting. comprising a rotatably supported cup-shaped wheelretainer, a grinding wheel having anoutside diameter adapted to entersaid retainer, .said grinding wheel having a hollow portion 23.1, the face opposite said retainer, said grinding wheel having lkeyways extending therethrough and :being positioned diametrically thereof, said cup-shaped retainer having apertures .in valinement with said keyways, a disk hav- 

